Prior art medical ultrasound systems comprise many subsystems, each subsystem needing to move data to a next subsystem for processing. A typical ultrasound system will employ first-in/first-out (FIFO) memory buffers for both receiving data from a preceding subsystem and for transferring data to a succeeding subsystem. Classically, each subsystem embodies the FIFO buffers via a dedicated memory device that is either housed with the subsystem or is directly tied to the subsystem for exclusive use thereof.
Such ultrasound systems have employed a parallel bus arrangement to enable communications between the various subsystems, the parallel bus provided with a number of slots to which the various subsystems could be coupled. Accordingly, subsystems which occupied slots on the bus passed data from one to another by transmitting and receiving data frames via the FIFO buffers.
While the use of a dedicated physical memory device for each subsystem insures that each has adequate access to its own specific data elements, a number of disadvantages are present in this design approach. Because multiple distinct physical memory devices are thus required, they are less able to meet changing system requirements in a cost effective manner (due to the need to change the multiple memory devices in the event of certain system modifications). Further, the multiple distinct physical memory devices exhibited a failure, size, weight, cost and power usage matrix that was less than optimal. For instance, the use of individual FIFO buffers for each subsystem allows only one read or one write memory access to occur at a give time in a given buffer. This constraint prevents certain functions from being performed in an overlapping manner and acts to reduce the overall processing time of the system.
Accordingly, there is a need for an ultrasound system that exhibits improved memory operation and utilization; that enables functions within the ultrasound system to be performed on an asynchronous, overlapping basis; and that makes use of relatively inexpensive commodity-type memory products.